Manufacture of unsaturated aliphatic carboxylic acids



United States Patent US. Cl. 260-533 14 Claims ABSTRACT OF THEDISCLOSURE A process for the manufacture of an unsaturated aliphaticcarboxylic acid, comprising reacting in the vapor phase at a temperatureranging from 200 to 500 C. an wolefin selected from the group consistingof propylene and isobutylene with molecular oxygen in the presence of acatalyst selected from the group consisting of the following formulas:

W Sn Mo Te O and W Co 'Sn Mo Te O wherein v is from 0.1 to 6, v from 0.1to 16, w from 1 to 5, x from 7 to 12.9, y from 0.1 to 5, z from 30 to 59and z is 30-83, and sum of v and x is 13.

This is a continuation-in-part of US. application Ser. No. 413,299 filedNov. 23, 1964, now abandoned.

This invention relates to the manufacture of unsaturated aliphaticcarboxylic acids. More particularly, the invention pertains to theoxidation of propylene or isobutylene in the vapor phase with molecularoxygen to produce acrylic acid or methacrylic acid in a single stepprocess.

There have been proposed in the prior art various processes for theconversion of a-olefins to the corresponding unsaturated carboxylicacids, which processes may be broadly classified into two categories,namely, the double step processing comprising oxidizing rx-OlCfins andthen oxidizing the resultant unsaturated aldehydes into the desiredunsaturated carboxylic acids; and the single step processing comprisingmanufacturing the desired unsaturated carboxylic acids directly from thestarting aolefins without intermediate steps. From the commercial andindustrial points of view, the latter process is manifestly desirable.

The aforesaid single step process, however, is not necessarilysatisfactory. The order of conversion of the starting a-olefins to thecorresponding unsaturated carboxylic acids is generally poor, and aconsiderable amount of unsaturated aldehydes is produced in admixtureWith the desired unsaturated carboxylic acids, so that the unreactedstarting a-olefins and intermediate aldehydes should be recycled if agood yield of the desired unsaturated carboxylic acids is to be secured.For instance, in Japa nese patent publication No. 4,209 (1962), 14,562(1963) and 19,260 (1963), British Patent 878,802 and Belgium Patent602,472, there are disclosed varied processes for the manufacture of thedesired unsaturated aliphatic carboxylic acids in a single step process.These processes, however, are not only poor in conversion of thestarting a-olefins but also produce a considerable amount of unsaturatedaldehydes as a byproduct, so that the resultant unsaturated aldehydesand unreacted olefins should be recycled for further conversion if theyield of the desired unsaturated carboxylic acids is to be improved.From the economic and industrial points of view, said recycling of3,487,109 Patented Dec. 30, 1969 the unreacted u-olefins and unsaturatedaldehydes is manifestly undesirable.

The major object of this invention is accordingly to provide a processfor the manufacture of acrylic acid or methacrylic acid in a single stepfrom propylene or isobutylene in a considerably high order of yield,namely, in a high order of conversion and selectivity, substantiallynecessitating no recycling of the unreacted olefins and the intermediatealdehydes.

Other objects and specific features of this invention will becomeapparent in view of the following:

The process of this invention for the manufacture of unsaturatedaliphatic carboxylic acids comprises contacting in the vapor phasepropylene or isobutylene with molecular oxygen in the presence of acatalyst of the formula:

W Sn Mo Te O wherein v is from 0.1 to 6, w from 1 to 5, x from 7 to12.9, y from 0.1 to 5 and z from 30 to 59, and the sum of v and x is 13.

The present invention is based upon the discovery that the catalyst ofthe above formula enables the starting propylene or isobutylene toconvert selectively in a single step into the corresponding unsaturatedaliphatic car- :boxylic acids, acrylic acid or methacrylic acid, in ahigh order of selective conversion without recycling the unreacteda-olefins and the unsaturated aldehydes. The amount of the resultantunsaturated aldehydes and other byproducts is negligible, and the perpass yield of the desired unsaturated carboxylic acids is markedlyimproved.

The catalyst of this invention consists of tungsten, tin, molybdenum,tellurium and oxygen in the order as disclosed in the aforesaid formula.Lack of any one element as specified in the formula results in areduction in conversion or selectivity, so that the objects of thisinvention cannot be attained. The known catalyst consisting of cobalt,molybdenum, tellurium and oxygen, for instance, invites a deteriorationin conversion if selectivity is to be enhanced and vice versa, so thatit is impracticable for said catalyst to improve the yield of theresultant unsaturated carboxylic acids in a single step. When thecatalyst of this invention is employed, on the other hand, conversionand selectivity are both raised to a high order, producing in a singlestep the desired unsaturated carboxylic acids in high yields. The termconversion and selectivity as herein employed are defined as below:

Percent conversion:

Number of moles of starting olefin fed number of moles of unreactedolefin Number of moles of starting olefin fed Percent selectivity:

Number of moles of each final product Number of carbon atoms of eachfinal pro duct Number of carbon atoms of starting olefin fed Number ofmoles of reacted olefin by atomic ratio and sum of W and M0 is 13.Preferable results are obtained in the atomic ratio of and sum of W andM0 is 13, the most desirable ratio being 1:l.9:l2:3:49 or thereabout.

There may be added to the catalyst of the aforesaid composition cobaltas one more metal component, forming the formula:

W Co 'Sn Mo Te O wherein v, w, x, and y are as defined before, v is from0.1 to 16 and z is 30-83. The presence of cobalt as an auxiliarycomponent makes it possible to attain a higher order of conversion andselectivity of the catalyst. Preferable atomic ratio of W:C:Sn:Mo:Te: isin the range of 0.2 3:1-11:1.2-4:l012.8:14:3672 and sum of W and M0 is13, the most desirable being 1:7:1.9:12:3:59 or thereabout.

The catalyst of the above formula is prepared by any of the conventionalmethods, such as precipitation and evaporation to dryness or mixing eachcomponent metal in the form of oxide. The catalyst containing cobalt mayfurther be prepared by adding cobalt in the form of a cobalt compound,such as cobalt oxide, to theW-Sn-Mo- Te-O catalyst.

The catalyst of the above formula may be regarded as a mixture of oxidesof the component metals, or a mixture of a heteropoly acid salt, such astin-tungsten-molybdate, and tellurium oxide, or a mixture of twoheteropoly acid salts, such as tin-molybdate and tin-tungstate, andtellurium oxide. But the exact chemical structure of said catalyst isyet unknown. Whether the structure is known or not, however, it has beenmade known for the first time in the art by the present inventors thatthe aforesaid catalyst has a property to produce the desired unsaturatedaliphatic carboxylic acids in markedly high yields.

The aforesaid catalyst of this invention is employed singly or inconjunction with a suitable support, such as silica, diatomaceous earth,alumina, silicon carbide, titanium oxide or zicronium oxide.

The starting olefins employed in this invention are propylene andisobutylene.

In the mechanism of the reaction involved in this invention, thestarting tit-olefins are oxidized into the corresponding aldehydes andthe resultant aldehydes are subsequently converted into the desiredcorresponding unsaturated aliphatic carboxylic acids. The catalyst ofthis invention can therefore be successfully applied to the oxilation ofunsaturated aldehydes to produce the corresponding unsaturatedcarboxylic acids in high yields. Even if there are present in the feedstock a-olefins and the corresponding 0:,[3-11I1S2t11f8t6d aldehydes inadmixture, said olefins or aldehydes are respectively converted into thecorresponding unsaturated aliphatic carboxylic acids, so that there canalso be employed as a feed stock a-0lefins containing the correspondingunsaturated aldehydes in various proportions. In this case a gas mixtureof propylene and acrolein or a mixture of isobutylene and methacroleinis preferably employed to produce the corresponding acrylic acid ormethacrylic acid in a yield as high as is the case with the singleemployment of propylene or isobutylene.

The range of amount of the oxygen to be fed to the reactor varieswidely, but good results are obtained when oxygen is employed in theorder of from 0.1 to moles, preferably from 3 to 12 moles, per mole ofthe starting a-olefin or the starting mixture of an a-olefin and thecorresponding aldehyde. The reaction mixture of the starting olefin andoxygen may be diluted, where desirable, with an inert gas, such ascarbon dioxide, nitrogen, saturated hydrocarbon or steam, so that air isadvantageously used as an oxygen source from the economic point of view.The most desirable diluent is steam as conversion and selectivity arestill more increased when the reaction gas is diluted with steam. Therange of amount of said diluents to be applied is very wide. To securethe desirable effects, however, steam is employed in the order of from 1to 60 moles, preferably from 5 to moles, per mole of the startinga-Olefin or the starting mixture of an OC-O'Ie' fin and thecorresponding aldehyde.

The reaction temperature employed in this invention ranges from 200 to500 C., preferably from 250 to 400 C. There is no appreciable efiect ofpressure on reaction. Hence the reaction may be conducted under normal,increased or reduced pressure, but normal atmospheric pressure ispreferred.

The time of contact of the gas mixture with the catalyst of theinvention can be varied widely. Satisfactory results, however, areobtained in the range of from 0.1 to 20 seconds, preferably from 1 to 10seconds. The term contact time as herein employed is defined as follows:

Contact time in second:

Apparent volume of the catalyst in the reactor Standardized volume ofgas fed to the reactor per unit The catalyst bed employed in thisinvention may be fixed or fluidized, of which the fluidized bed ispreferablebecause of its ability to prevent the reaction system from theoccurrence of hot spots due to the exothermic reaction.

Besides the desired unsaturated aliphatic carboxylic acids, the gaseousproduct from the reactor contains a small amount of unreacted startinggases, unsaturated aldehydes, saturated carboxylic acids, carbonmonoxide and carbon dioxide. The desired unsaturated aliphaticcarboxylic acids are separated from said products in accordance with theknown methods, such as condensation or extraction with water or othersuitable solvents.

In order to afford a fuller understanding of the principles of thisinvention, there are provided the following examples which areillustrative only and not limiting the invention:

EXAMPLE 1 In 1,800 cc. of hot water were dissolved with stirring 55grams of ammonium paratungstate of a formula (NH W O -3H O, 445 grams ofammonium paramolybdate of a formula (NH Mo O -4H O, and 104 grams ofammonium chloride. There were then added dropwise 123 grams of stannicchloride of a formula SnCl -3H O dissolved in 150 cc. of water. Themixture was heated with stirring for further 45 minutes, and theprecipitates were filtered, washed with water and dried.

Whole amount of the resultant precipitates were heated with stirring in460 cc. of water. To the resultant mixture were added 80.4 grams ofmetal tellurium dissolved in 280 cc. of nitric acid in 280 cc. of water.The mixture was heated and evaporated with stirring and the driedmixture was pelleted, dried and heated in air stream at 400 C. for 4hours. The resultant catalyst was confirmed to have an atomic ratio ofcc. of the catalyst were filled in a U-shaped stainless steel reactor,25 mm. in internal diameter, and the reactor was dipped in a nitratebath heated to 330 C. Into this reactor was introduced a gas mixture of1 percent by volume of propylene, 60 percent by volume of air, and 39percent by volume of steam, and reacted by contact for 1.8 seconds. Theresultant reaction products were water scrubbed and analyzed. Resultsobtained were as follows:

Conversion of propylene:

Selectivity=Acrylic acid: 62.5%, acetic acid: 2.2%, acrolein: 7.0%,carbon dioxide: 12.5%, carbon monoxide: 12.3%, others: 3.5%.

EXAMPLE 2 Whole amount of the precipitates obtained by the same manneras in Example 1 were stirred in 460 cc. of water and to the solutionwere added 427 grams of cobalt nitrate of a formula Co(NO -6H Odissolved in 300 cc. of water. There were then added 80.4 grams of metaltellurium dissolved in 280 cc. of nitric acid in 280 cc. of water. Themixture was then heated with stirring for evaporation, pelleted, dried,and heated in air stream at 400 C. for 4 hours. The resultant catalystwas confirmed to have an atomic ratio of W:Co:Sn:Mn:Te:O=1:7: 1.9112359.

80 cc. of the catalyst were filled in a U-shaped stainless steelreactor, 25 mm. in internal diameter, and the reactor was dipped in anitrate bath heated to 350 C. Into this reactor was introduced a gasmixture of 1 percent by volume of propylene, 60 percent by volume ofair, and 39 percent by volume of steam, and reacted by contact for 1.8seconds. Results obtained were as follows:

Conversion of propylene: 93.0%.

Selectivity=Acrylic acid: 70.5%, acetic acid: 2.0%, acrolein: 5.5%,carbon dioxide: 12.3%, carbon monoxide: 8.6%, others: 1.1%.

EXAMPLE 3 80 cc. of the catalyst of Example 2 were filled in a U-shapedstainless steel reactor, 25 mm. in internal diameter, and the reactorwas dipped in nitrate bath heated to 340 C. Into this reactor wasintroduced a gas mixture of 1 percent by volume of propylene, 60 percentby volume of air, and 39 percent by volume of nitrogen, and reacted bycontact for 1.5 seconds. Results obtained were as follows:

Conversion of propylene: 94.5%.

Selectivity=Acrylic acid: 55.2%, acetic acid: 3.0%, acrolein: 3.9%,carbon dioxide: 24.1%, carbon monoxide: 11.5%, others: 2.3%.

EXAMPLE 4 60 cc. of the catalyst of Example 2 were filled in a U-shapedstainless steel reactor, 25 mm. in internal diameter, and the reactorwas dipped in a nitrate bath heated to 300 C. Into this reactor wasintroduced a gas mixture of 1 percent by volume of isobutylene, 60percent by volume of air, and 39 percent by volume of steam, and reactedby contact for 0.9 second. Results obtained were as follows:

Conversion of isobutylene: 81.2%.

Selectivity=Methacrylic acid: 47.7%, acetic acid: 7.8%, methacrolein:1.2%, carbon dioxide: 20.1%, carbon monoxide: 13.1%, others: 11.1%.

EXAMPLE 5 Whole amount of the precipitates prepared by the same manneras in Example 1 were stirred in 460 cc. of hot water. There were thenadded with stirring 427 grams of cobalt nitrate of a formula Co(NO -6H Odissolved in 300 cc. of water, and then 64.2 grams of metal telluriumdissolved in 224 cc. of nitric acid in 224 cc. of water. To theresultant mixture were further added 279 grams of anatase type titaniumoxide of a particle size of from 0.2 to 0.4 micron, and the mixture washeated with stirring for evaporation, pelleted, dried and heated in airstream at 400 C. for 4 hours. The resultant catalyst was confirmed tohave an atomic ratio of W:Co:Sn:Mo:Te: O:(TiO )=1:7:1.9:12:2.4:58:17.

80 cc. of the catalyst were filled in a U-shaped stainless steelreactor, 25 mm. in internal diameter, and the reactor was dipped in anitrate bath heated to 350 C. Into this reactor was introduced a gasmixture of 1 percent by volume of propylene, 60 percent by volume ofair, and 39 percent by volume of steam, and reacted by contact for 1.8seconds. Results obtained were as follows:

Conversion of propylene: 91.0%.

Selectivity=Acrylic acid: 71.3%, acetic acid: 2.1%, acrolein: 7.0%,carbon dioxide: 11.0%, carbon monoxide: 7.6%, others: 1.0%.

EXAMPLE 6 Whole amount of the precipitates obtained by the same manneras in Example 1 were stirred in 460 cc. of hot water. There were thenadded 427 grams of cobalt nitrate of a formula Co(NO -6H O dissolved in300 cc. of water, and 64.2 grams of metal tellurium dissolved in 224 cc.of nitric acid in 224 cc. of water. To the resultant mixture werefurther added 279 grams of zirconium oxide particles, and the mixturewas heated with stirring for evaporation, pelleted, dried, and heated inair stream at 400 C. for 4 hours. The resultant catalyst was confirmedto have an atomic ratio of W:Co:Sn:Mo: Te:O:(ZrO)==1:7:1.9:12:2.4:58:11.

cc. of the catalyst were filled in a U-shaped stainless steel reactor,25 mm. in internal diameter, and the reactor was dipped in a nitratebath heated to 340 C. Into this reactor was introduced a gas mixture of1 percent by volume of propylene, 60 percent by volume of air, and 39percent by volume of steam, and reacted by contact for 1.8 seconds.Results obtained were as follows:

Conversion of propylene: 92.4%.

Selectivity=Acrylic acid: 70.0%, acetic acid: 2.4%, acrolein: 5.0%,carbon dioxide: 11.9%, carbon monoxide: 8.3%, others: 2.4%.

EXAMPLE 7 Whole amount of the precipitates obtained by the same manneras in Example 1 were stirred in 460 cc. of hot water. There were thenadded 427 grams of cobalt nitrate of a formula Co(NO -6H O dissolved in300 cc. of water, and then 64.2 grams of metal tellurium dissolved in224 cc. of nitric acid in 224 cc. of water. To the resultant mixturewere further added 279 grams of diatomaceous earth, and the mixture washeated with stirring for evaporation, pelleted, dried and heated in airstream at 400 C. for 4 hours. The resultant catalyst wa confirmed tohave an atomic ratio of W:Co:Sn:Mo:Te:O:(SiO )=1:7: 1.9: 12:2.4:58:22

80 cc. of the resultant catalyst were placed in a U- shaped stainlesssteel reactor, and the reactor was dipped in a nitrate bath heated to360 C. Into this reactor was introduced a gas mixture of 1.5 percent byvolume of propylene, 60 percent by volume of air, and 38.5 percent byvolume of steam, and reacted by contact for 2.2 seconds. Resultsobtained were as follows:

Conversion of propylene: 89.8%.

Selectivity=Acrylic acid: 73.2%, acetic acid: 2.1%, acrolein: 7.0%,carbon dioxide: 10.2%, carbon monoxide: 6.7% others: 0.8%.

EXAMPLE 8 80 cc. of the catalyst of Example 2 were placed in a U-shapedstainless steel reactor, 25 mm. in internal diameter, and the reactorwas dipped in a nitrate bath heated to 350 C. Into this reactor wasintroduced a gas mixture of 0.2 percent by volume of propylene and 1.0percent by volume of acrolein, 60 percent by volume of air, and 38.8percent by volume of steam, and reacted by contact for 1.8 seconds.Number of moles of each component in the resultant product on the basisof moles as total of the propylene and acrolein fed were as follows:

Acrylic acid: 79.0 moles, acetic acid: 1.4 mole, acrolein: 2.1 moles,carbon dioxide: 8.7 moles, carbon monoxide: 7.9 moles, others: 0.9moles.

EXAMPLE 9 60 cc. of the catalyst of Example 2 were placed in a U-shapedstainless steel reactor, 25 mm. in internal diameter, and the reactorwas dipped in a nitrate bath heated to 350 C. Into this reactor wasintroduced a gas mixture of 1.5 percent by volume of acrolein, 60percent by volume of air, and 38.5 percent by volume of steam, andreacted by contact for 1.3 seconds. Results obtained were as follows:

Conversion of acrolein: 90.6%.

Selectivity=Acrylic acid: 90.3%, acetic acid: 2.2%, carbon dioxide:3.7%, carbon monoxide: 1.8%, others: 2.0%.

EXAMPLE 10 Another series of runs were made employing the catalyst ofExample 1 in which the amount of metal tellurium content was varied asspecified in the subsequent table. Thus the catalysts of atomic ratio ofW:Sn:Mo:Te:O=1:1.9:12:y:z, in which y and z were specified in the table,were obtained. Reaction conditions were identical to those employed inExample 1. Results obtained were as follows:

cobalt nitrate was varied as specified in the subsequent table. Thus thecatalysts of atomic ratio of W:Co:Sn:Mo:Te:O=1:v':l.9:12:3:z'

in which v' and z are specified in the table, were obtained. Reactionconditions were identical to those employed in Example 2. Resultsobtained were as follows:

Catalyst No.

Metal tellurium added in grams percent of propylen Selectivity inpercent:

Acrylic acid 5. 15. 18. Others 4.

EXAMPLE 1 1 Further series of runs were conducted employing the catalystof Example 1 in which the amount of ammonium paratungstate and that ofammonium paramolybdate were varied as specified in the subsequent table.Thus the catalysts of atomic ratio of W:Sn:Mo:Te:O=v:1.9:x:3:49

in which v and x are specified in the table, were obtained.

Reaction conditions were identical to those employed in Example 1.Results obtained were as follows:

Catalyst No.

Ammonium paratungstate in grams Ammonium paramolybdate in grams.

Others EXAMPLE 12 Still further series of runs were performed employingthe catalyst of Example 1 in which the amount of stannic chloride wasvaried as specified in the subsequent table. Thus the catalysts ofatomic ratio of W:Sn:Mo:Te:O=l:w:12:3:z

in which w and z are specified in the table, were obtained.

Reaction conditions were identical to those employed in Example 1.Results obtained were as follows:

Catalyst No.

Conversion in percent of propylene 70. 9 83. 7 100 Selectivity inpercent:

Acrylic acid 44. 2 53.

Acetic acid. 2.

$3 o: a O Camp--10: wad en Stannic chloride added in grams Acroleiu .1Carbon dioxide Carbon monoxide- EXAMPLE 13 A still another series ofruns were conducted employing the catalyst of Example 2 in which theamount of Catalyst No.

v Conversion in percent Selectivity in percent Acrylic acid Acetic acidAcrolein.

EXAMPLE 14 Catalyst No.

Ammonium paratungstate in grams Stannic chloride added in grams Ammoniumparamolybdate in grams Metal tellurium added in grams Conversion inpercent of propylen Selectivity in percent:

Acrylic acid Acetic acid EXAMPLE 15 Another series of runs wereconducted employing the catalyst of Example 2 in which the amount ofammonium paratungstate, cobalt nitrate, stannic chloride, ammoniumparamolybdate and metal tellurium was varied as specified in thesubsequent table. Thus the catalysts of atomic ratio ofW:Co:Sn:Mo:Te:O=v:v'zwrxzyzz in which v, v, w, x, y and z are specifiedin the table, were obtained. Reaction conditions were identical to thoseemployed in Example 2. Results obtained were as follows:

Catalyst No.

Ammonium paratungstate in grams 165 Cobalt nitrate added in grams. 671Stannic chloride added in grams, 259 Ammonium paramolybdate in grams.475 445 371 26. 8 80. 4 107 Metal tellurium added in grams 0. 2 1 3 v'..1 7 11 w 1. 2 1. 9 4 I- 12. 8 12 10 1h 1 3 4 z 45 59 72 Conversion inpercent of propylene 82. 1 96. 4 83. 0 Selectivity in percent:

Acrylic acid- 53.1 70. 3 52. 3 Acetic acid- 4. 2 1. 4 2. 9 Acro1ein 20.0 9. S 13. 3 Carbon dioxide 10.0 11. 6 15. 1 Carbon oxide 7. 7 6. 1 13.Others 5. 0 0. 8 2. 9

In view of the foregoing, it may be apparent that various changes andmodifications can be made in the principles of this invention withoutdeparting from the scope and spirit of the same. It is accordinglyrequested that the invention be understood rather broadly exceptotherwise described.

We claim:

1. A process for the manufacture of an unsaturated aliphatic carboxylicacid, comprising reacting in the vapor phase at a temperature rangingfrom 200 to 500 C., an a-olefin selected from the group consisting ofpropylene and isobutylene with molecular oxygen in the presence of acatalyst selected from the group consisting of the following formulas:

W Sn Mo Te O and W Co 'Sn Mo Te O wherein v is from 0.1 to 6, v from 0.1to 16, w from 1 to 5, x from 7 to 12.9, y from 0.1 to 5, z from 30 to 59and z is 30-83, and sum of v and xis 13.

2. The process of claim 1, wherein said zx-olefin is propylene.

3. The process of claim 1, wherein said u-olefin is propylene,isobutylene.

4. The process of claim 1, in which said a-olefin is used in combinationwith the corresponding 0a,;3-111'1S31L1- rated aldehyde.

5. The process of claim 4, wherein said gas mixture consists ofpropylene and acrolein.

6. The process of claim 4, where said gas mixture consists ofisobutylene methacrolein.

7. The process of claim 1, Where the atomic ratio of W, Sn, Mo, Te and Oof said catalyst is and sum of W and Mo is 13.

8. The process of claim 1, wherein the atomic ratio of W, Co, Sn, Mo, Teand O of said catalyst is and sum of W and M0 is 13.

9. The process of claim 7, wherein the atomic ratio of W, Sn, Mo, Te andO of said catalyst is 10. The process of claim 8, where the atomic ratioof W, Co, Sn, Mo and Te of said catalyst is 11. The process of claim 1,wherein the reaction gas to be employed contains molecular oxygen in therange of from 0.1 to 20 moles per mole of the starting olefin.

12. The process of claim 4, wherein the reaction gas to be employedcontains molecular oxygen in the range of from 0.1 to 20 moles per moleof the starting gas mixture of an a-olefin and the corresponding eo-unsaturated aldehyde.

13. The process of claim 1, wherein the reaction gas contains steam asdiluent in the range of from 1 to moles per mole of the starting olefin.

14. The process of claim 4, wherein the reaction gas contains steam asdiluent in the range of from 1 to 60 moles per mole of the starting gasmixture of an a-olefin and the corresponding 0:,[3-1111S3tl1l'3t6daldehyde.

References Cited UNITED STATES PATENTS 3,240,806 3/1966 Bethell et al.260--533 JAMES A. PATTEN, Primary Examiner D. STENZEL, AssistantExaminer US. Cl. X.R. 252439

